The follow-through is often misunderstood in putting. Using a thump hoop, place the ball under it and make a stroke. My putter head moved just 1/4 inch past impact, yet the ball rolled 15 feet. This demonstrates that acceleration happens at the start of the downswing, not at impact.
You can also try this drill with two tees positioned in the ground. Make the same stroke, letting the tees stop your putter head for better control and feel.
